<?php

class customException extends Exception
{
	public function errorMessage(){
		//error message
		$errorMsg = 'Error on line '.$this->getLine().' in '.$this->getFile()
		.': <b>'.$this->getMessage().'</b> is not a valid E-Mail address';
		return $errorMsg;
	}
}

$email = "someone@example.com";

try{
	//check if 
	if(filter_var($email, FILTER_VALIDATE_EMAIL) === FALSE){
		//throw exception if email is not valid
		throw new customException($email);
	}
	//check for "example" in mail address
	if(strpos($email, "example") !== FALSE){
		throw new Exception("$email is an example e-mail");
	}
}

catch (customException $e){
	echo $e->errorMessage();
}

catch(Exception $e){
	echo $e->getMessage();
}

 ?>